Dimethyl sulfoxide: an inhibitor of liver alcohol dehydrogenase.

Dimethyl sulfoxide inhibits horse liver alcohol dehydrogenase. In the direction of aldehyde reduction, this inhibition is competitive with aldehyde, with an inhibition constant of 5 x 10(-3)M. Dimethyl sulfoxide reacts with the binary complex consisting of enzyme and the reduced form of nicotinamide -adenine dinucleotide to form a highly fluorescent ternary complex, with a dissociation constant similar to the inhibition constant.